Sends response headers.
The SendHeaders Method syntax has these parts:
||An expression evaluating to an object
of type WebResponse.
This method will send response headers to the client, but will
not send response body - yet. You are free to change response body
in the meantime, and call Response.Send
method when you want it to be delivered completely. Or, you can call
TransferEncoding property is set to ChunkedEncoding) to
send parts of the response. Once again, when you want response to be
fully delivered, call Response.Send method.